This invention concerns catamenial tampons and more specifically, those catamenial tampons known as digital tampons which are designed to be inserted with the fingers and without the aid of such devices as plungers or stick-type applicators.
While many and varied configurations exist for the applicator-type tampon, heretofore the design and choice of materials for the construction of digital tampons have been limited by certain constraints. Since the digital type of tampon is designed to be inserted with only the assistance of the fingers, it is essential that the tampon be rigid enough to penetrate the introitus of the vagina in opposition to the muscular forces which tend to keep that orifice closed. Also, once past the introitus, the tampon must maintain a sufficient degree of rigidity to allow proper placement in the vaginal vault. Further, to avoid discomfort during insertion, the rigid tampon must be generally of a small diameter, approximately 1.2 to about 1.7 centimeters, and of a length no greater than about 5 centimeters. Needless to say, in addition to the constraints of rigidity and size, the tampon must be able to capture, i.e., absorb, entrap and/or retain, a sufficient quantity of menses. The tampon should also be capable of expanding when wet to minimize the possibility of menstrual fluid bypassing an emplaced tampon.
These constraints have until now greatly limited the choice of materials and hence, the functional properties of digital tampons. Such digital tampons as are presently on the market comprise a mass of cellulosic fibers such as cotton, rayon, wood pulp or the like, compressed into a generally cylindrical, rigid tampon shape. The cellulosic fibers will maintain their compressed shape when dry and when wet will expand somewhat to hold absorbed menses. The absorbency of such tampons is essentially prescribed by the size limitations set out above. A mass of cellulose fibers can be compressed to a limiting maximum density before a detrimental effect in absorbency is encountered. Because of this, given the above size limitations, only a limited weight of fiber can be provided in a tampon and hence the maximum capacity of the tampon to absorb menses is prescribed. Further, since certain absorbent materials such as hydrophilic polyurethane foams and absorbent powders to do not readily compress into rigid bodies, to date the use of such materials in digital tampons has been precluded. Thus, while great progress has been made in the area of applicator-type tampons, the constraints of size and rigidity have greatly inhibited any enhancement of absorption capacity in digital tampons.